The present invention relates to elastic suction plates for vacuum systems. Suction cups, respectively suction plates, made of elastically deformable material, connected to the low-pressure system by means of rigid, mostly metal parts, are suitable for lifting and transporting compact objects with an essentially even surface. When such a suction plate comes into contact with the object to be lifted and a low pressure is produced in the hollow space therebetween, major forces can be transmitted. With this method, it is in particular possible to lift relatively heavy objects easily for transporting them to the desired place and to deposit them by releasing the low pressure.
In the case of objects which are not delicate, no particular problems occur. It is only required that the suction plate is provided with a flexible lip along its outer edge, resulting in a tight seal between the suction plate and the object to be lifted.
There are difficulties however when delicate objects, in particular those with a not very resistant surface, need to be lifted by means of low-pressure suction plates. It is for instance desirable to handle "fresh" concrete interlocking paving stones immediately after their manufacture, although sufficient strength for doing so would be reached only after several days. Suction plates known for such applications are often not satisfactory. Problems occur particularly with interlocking paving stones with "face mix concrete", i.e. stones having relatively thin, mostly fine-grained upper surfaces, which are often not homogenously connected with the "core concrete" covered by said "face mix concrete" layer.
All these difficulties are overcome with the suction plate according to the present invention which is described below with regard to FIGS. 3-9.